Mark William Rudd (born June 2, 1947) is an American political organizer, mathematics instructor, anti-war activist and counterculture icon who got involved with the Weather Underground in the 1960s. Rudd became a member of the Columbia University chapter of Students for a Democratic Society (SDS) in 1963. By 1968, he had emerged as a leader for Columbia's SDS chapter. During the 1968 Columbia University Protests, he served as spokesperson for dissident students protesting a variety of issues, particularly the Vietnam War. As the war escalated, Mark Rudd worked with other youth movement leaders to take SDS in a more militant direction. While much of the general membership of SDS refused to countenance violence, Rudd together with some other prominent SDS members formed a paramilitary organ